We constructed a bioenergetics model for sockeye salmonOncorhynchus nerkaand evaluated its sensitivity to parameter error. When used to predict annual growth, the model was most sensitive, in declining order of importance. to changes in the intercept of the dependence of consumption on body weight, the proportion of maximum consumption, the energy density of prey, low temperature and its associated proportion of maximum consumption in the temperaturedependence function, the intercept of the energy density relationship to predator weight, and the intercept of the relationship between body weight and respiration. Estimates of consumption from the model, when consumption was constrained by fixed growth, were quite insensitive to perturbation of all parameters except the energy density of prey. We computed consumption rates and energy budgets with the model and compared these with independently derived estimates for populations in Lake Dalnee, USSR; Lake Washington, USA; and Babine Lake, Canada. The close agreement of estimates from the model to independent estimates of prey consumption and energy budgets for three different populations indicated that the model may be widely applicable to other populations. Performance of the model can be enhanced further if the frequency with which water temperature and mean body weight data are collected is increased for each cohort of interest.